Extended-release topiramate capsules

ABSTRACT

An extended-release topiramate capsule that includes a capsule shell containing a single population of coated particles; wherein each coated particle includes a core and a coating thereon; wherein each particle core includes a homogeneous mixture comprising topiramate throughout its core; and wherein the coating includes one or more release controlling agent(s).

CONTINUING APPLICATION DATA

This application claims the benefit of U.S. Provisional Application Ser. No. 61/779,576, filed Mar. 13, 2013, and also claims the benefit of U.S. Provisional Application Ser. No. 61/788,880, filed Mar. 15, 2013, each of which is incorporated by reference herein.

BACKGROUND

The pharmaceutical industry employs a variety of dosage formulations for orally administering medicinal agents to patients. Typical formulations for oral administration include liquid solutions, emulsions, or suspensions, as well as solid forms such as capsules or tablets (as used herein, the term “tablet” means any shaped and compressed solid dosage form, including caplets).

Efficacy of a drug product often depends on patient compliance with a dosing schedule. Therefore, one per day, extended-release, dosages have better efficacy over the long term than multidose regimens.

SUMMARY

The present disclosure provides solid dosage formulations of topiramate [2,3:4,5-bis-O-(1-methylethylidene)-β-D-fructopyranose sulfamate], particularly capsules, containers including such capsules, and methods of dosing.

In one embodiment, the present disclosure provides an extended-release formulation that is dosed once-per-day, in the form of a capsule.

In one embodiment, the present disclosure provides an extended-release topiramate capsule that includes a capsule shell and a single population of coated particles contained within the capsule shell, wherein each coated particle includes a core and a coating thereon. In certain embodiments, the particles, whether coated or uncoated, are spherical.

Each particle core includes a homogeneous mixture including topiramate throughout the core. In certain embodiments, each particle core also includes a filler and/or a binder (preferably, both a filler and a binder) in the homogeneous mixture.

The coating includes a release controlling agent. In certain embodiments, the coating also includes a pore former and/or a plasticizer.

In one embodiment, an extended-release topiramate capsule is provided that includes: a capsule shell containing a single population of coated particles; wherein each coated particle includes a core and a coating thereon; wherein each particle core includes a homogeneous mixture throughout its core, the mixture including: 40 wt-% to 50 wt-% of topiramate, based on the total weight of an uncoated particle core; 45 wt-% to 55 wt-% of one or more filler(s), based on the total weight of an uncoated particle core; and 3 wt-% to 7 wt-% of one or more binder(s), based on the total weight of an uncoated particle core; wherein the coating includes: 55 wt-% to 65 wt-% of one or more release control agent(s), based on the total weight of the coating; 20 wt-% to 25 wt-% of one or more pore former(s), based on the total weight of the coating; and 10 wt-% to 20 wt-% of one or more plasticizer(s), based on the total weight of the coating; wherein the particles are coated in an amount sufficient to provide a (coating)weight gain of 8% to 14%.

As used herein, the terms “topiramate active agent” and “active agent of topiramate” and “topiramate” are synonymous and are used interchangeably throughout the specification to refer to the compound 2,3:4,5-bis-O-(1-methylethylidene)-β-D-fructopyranose sulfamate. Included within these terms are also pharmaceutically acceptable salts thereof as well as polymorphs, solvates, hydrates, dehydrates, co-crystals, anhydrous, and amorphous forms thereof.

The term “extended-release” means release of an active agent over a period of time, which is much longer than the release from an immediate release formulation, which usually releases more than 80% of the active agent in 60 minutes or less.

The term “therapeutically effective amount” as used herein means that amount of active compound that elicits the biological or medicinal response in a tissue, system, animal or human that is being sought by a researcher, veterinarian, medical doctor or other clinician, which includes alleviation and/or prevention of the symptoms of the condition being treated.

The terms “comprises” and variations thereof do not have a limiting meaning where these terms appear in the description and claims. Such terms will be understood to imply the inclusion of a stated step or element or group of steps or elements but not the exclusion of any other step or element or group of steps or elements. By “consisting of” is meant including, and limited to, whatever follows the phrase “consisting of.” Thus, the phrase “consisting of” indicates that the listed elements are required or mandatory, and that no other elements may be present. By “consisting essentially of” is meant including any elements listed after the phrase, and limited to other elements that do not interfere with or contribute to the activity or action specified in the disclosure for the listed elements. Thus, the phrase “consisting essentially of” indicates that the listed elements are required or mandatory, but that other elements are optional and may or may not be present depending upon whether or not they materially affect the activity or action of the listed elements.

The words “preferred” and “preferably” refer to embodiments of the disclosure that may afford certain benefits, under certain circumstances. However, other embodiments may also be preferred, under the same or other circumstances. Furthermore, the recitation of one or more preferred embodiments does not imply that other embodiments are not useful, and is not intended to exclude other embodiments from the scope of the disclosure.

As used herein, “a,” “an,” “the,” “at least one,” and “one or more” are used interchangeably. Thus, for example, a particle core that comprises “a” binder can be interpreted to mean that the particle core includes “one or more” binders. Similarly, a coating comprising “a” pore former can be interpreted to mean that the composition includes “one or more” pore formers.

As used herein, the term “or” is generally employed in its usual sense including “and/or” unless the content clearly dictates otherwise.

The term “and/or” means one or all of the listed elements or a combination of any two or more of the listed elements (e.g., preventing and/or treating an affliction means preventing, treating, or both preventing and treating an affliction).

Also herein, all numbers are assumed to be modified by the term “about” and preferably by the term “exactly.” As used herein in connection with a measured quantity, the term “about” refers to that variation in the measured quantity as would be expected by the skilled artisan making the measurement and exercising a level of care commensurate with the objective of the measurement and the precision of the measuring equipment used.

Also herein, the recitations of numerical ranges by endpoints include all numbers subsumed within that range as well as the endpoints (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, 5, etc.). Herein, “up to” a number (e.g., up to 50) includes the number (e.g., 50).

The above summary of the present disclosure is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The description that follows more particularly exemplifies illustrative embodiments. In several places throughout the application, guidance is provided through lists of examples, which examples can be used in various combinations. In each instance, the recited list serves only as a representative group and should not be interpreted as an exclusive list.

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present disclosure provides solid dosage formulations of topiramate [2,3:4,5-bis-O-(1-methylethylidene)-β-D-fructopyranose sulfamate]. Such solid dosage formulations are extended-release once-per-day dosage capsules (i.e., designed for administration once per day).

In one embodiment, the present disclosure provides an extended-release topiramate capsule that includes a capsule shell and a single population of coated particles contained within the capsule shell. In this context, “a single population” means that all the particles in one capsule are the same (within reasonable manufacturing variability) with respect to composition. In this context, “same” means the particles in one capsule are made in a single batch process or in multiple batches using identical processes.

The use of a single population of particles in any one capsule provides significant advantages from a manufacturing (e.g., quality and cost) perspective. For example, different populations of particles (e.g., beads), having different compositions, do not need to be manufactured for one product.

Furthermore, in certain embodiments, the capsules of the present disclosure do not include an immediate release component in any significant amount. Typically, capsules of the present invention are free of an immediate-release component.

Each coated particle includes a core and a coating thereon. In certain embodiments, the particles, whether coated or uncoated, are spherical, as defined in greater detail below.

Each particle core includes a homogeneous mixture including topiramate throughout the core. In certain embodiments, each particle core also includes a filler and/or a binder (preferably, both a filler and a binder) in the homogeneous mixture.

The coating on each core includes a release controlling agent. In certain embodiments, the coating also includes a pore former and/or a plasticizer.

In one embodiment, the present disclosure provides a solid dosage formulation that includes a capsule including core particles with a coating thereon. The core particles include the active agent. The core particles can also include a filler and/or a binder (preferably, both a filler and a binder). The coating includes a release-controlling agent. The coating can also include a pore former and/or a plasticizer.

In certain embodiments, the particles, whether coated or uncoated, are spherical. In this context, the term “spherical” refers to particles that are generally rounded by visual inspection. They may or may not be perfectly spherical. A representative population of spherical particles (i.e., beads) typically has an average sphericity of at least 0.7. In certain embodiments, the average sphericity of a representative population of particles is at least 0.75, and in certain embodiments at least 0.8. A preferred sphericity is 0.8. Sphericity can be determined by use of a digital microscope and a two-dimensional image analysis software (e.g., such as that by Soft Imaging System GmbH, version 5.0 Build 1054).

In certain embodiments, the particle size (which is typically the diameter of a spherical particle) of the coated particles is at least 500 μm (microns). In certain embodiments, the particle size of the coated particles is up to 1300 μm. In certain embodiments, the majority of the particles in a capsule are typically in a range of 700 μm to 1000 μm.

The rate of particle dissolution is typically dependent on the coating weight, which can be adjusted during manufacture. In certain embodiments, the particles are coated in an amount sufficient to provide a weight gain of at least 2%, or at least 4%, or at least 6%, or at least 8%, or at least 9%, or at least 10%. In certain embodiments, the particles are coated in an amount sufficient to provide a weight gain of up to 30%, or up to 25%, or up to 20%, or up to 15%, or up to 12%. Preferably, the particles are coated in an amount sufficient to provide a weight gain of 10% to 12%. In certain embodiments, the particles are coated in an amount sufficient to provide a weight gain of 8% to 14%.

In this context, “weight gain” is defined as the theoretical weight gain of a population of particles as a result of coating, assuming 100% coating efficiency. Thus, “weight gain” refers to coating weight gain. As an example, 100 grams of uncoated particles (e.g., beads) coated to a theoretical weight gain of 8% means that an amount of coating solution having 8 grams (g) of non-volatile components, e.g., release controlling agent, pore former, and plasticizer, was applied to the uncoated beads in a coating step, but there may be some losses in the manufacturing process.

Suitable active agents within the particle core include topiramate (2,3:4,5-bis-O-(1-methylethylidene)-β-D-fructopyranose sulfamate). “Topiramate” refers to 2,3:4,5-bis-O-(1-methylethylidene)-β-D-fructopyranose sulfamate as well as pharmaceutically acceptable salts of topiramate, including without limitation, topiramate sodium, topiramate lithium, topiramate potassium, as well as polymorphs, solvates, hydrates, dehydrates, co-crystals, anhydrous, and amorphous forms thereof. Topiramate can be purchased from commercial sources. It is presently available for marketing as an immediate-release tablet product (as TOPAMAX) for certain seizure indications and migraine prophylaxis.

An amount of topiramate active agent is included within a capsule in an amount sufficient to deliver the desired dose. Alternatively stated, a therapeutically effective amount of topiramate is included within a capsule. A capsule can include a topiramate active agent in an amount of at least 10 weight percent (wt-% or % w/w), or at least 25 wt-%, or at least 35 wt-%, or at least 40 wt-%, or at least 44 wt-%, based on the total weight of an uncoated particle core. A capsule can include a topiramate active agent in an amount of up to 80 wt-%, or up to 50 wt-%, or up to 46 wt-%, based on the total weight of an uncoated particle core. In certain embodiments, the particle cores of the capsules of the present disclosure include 40 wt-% to 50 wt-% topiramate active agent, based on the total weight of an uncoated particle core. In certain embodiments, the particle cores of the capsules of the present disclosure include 44 wt-% to 46 wt-% topiramate active agent, based on the total weight of an uncoated particle core.

The active agent can be homogeneously mixed within a particle core that includes one or more fillers and/or binders. One or more stabilizers can also be included in the particle core. Inclusion of a stabilizer may help maintain the potency of topiramate over time.

Herein, for any component specified, if there are multiple grades (e.g., molecular weights) of such component, recitation of the component implies any or all of such variations.

Suitable fillers for use in the particle cores include, but are not limited to, microcrystalline cellulose, dibasic calcium phosphate, lactose, tribasic calcium phosphate, mannitol, other suitable carbohydrates (e.g., other sugars or starches). Combinations of fillers can be used if desired. Preferably, microcrystalline cellulose is used as a filler (such as that available from JRS Pharma under the trade designation EMCOCEL 90M).

One or more fillers can be used in an amount of at least 10 wt-%, or at least 25 wt-%, or at least 45 wt-%, or at least 48 wt-%, based on the total weight of the uncoated particle core. One or more fillers can be used in an amount of up to 85 wt-%, or up to 75 wt-%, or up to 55 wt-%, or up to 52 wt-%, based on the total weight of the uncoated particle core. In certain embodiments, the particle cores of the capsules of the present disclosure include 45 wt-% to 55 wt-% filler(s), based on the total weight of an uncoated particle core. In certain embodiments, the particle cores of the capsules of the present disclosure include 48 wt-% to 52 wt-% filler(s), based on the total weight of an uncoated particle core.

Suitable binders for use in the particle core include, but are not limited to, hydroxypropyl methylcellulose (i.e., hypromellose or “HPMC”), methylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, hydroxypropyl cellulose, hydroxyethylcellulose, polyvinyl pyrrolidine (i.e., povidone), starch (e.g., pregelatinized starch), and natural gum (e.g., acacia gum, sodium alginate, guar gum, xanthan gum). Combinations of binders can be used if desired. Preferably, hydroxypropyl methylcellulose (hypromellose 2910) is used as a binder (such as that available from The Dow Chemical Company under the trade designation METHOCEL E5 Premium).

One or more binders can be used in an amount of at least 1 wt-%, or at least 2 wt-%, or at least 3 wt-%, or at least 4 wt-%, based on the total weight of the uncoated particle core. One or more binders can be used in an amount of up to 10 wt-%, or up to 9 wt-%, or up to 8 wt-%, or up to 7 wt-%, or up to 6 wt-%, based on the total weight of the uncoated particle core. In certain embodiments, the particle cores of the capsules of the present disclosure include 3 wt-% to 7 wt-% binder(s), based on the total weight of an uncoated particle core. In certain embodiments, the particle cores of the capsules of the present disclosure include 4 wt-% to 6 wt-% binder(s), based on the total weight of an uncoated particle core.

Particles described herein can further include a stabilizer, preferably in the core. Suitable stabilizers for use in the particle core include, but are not limited to, calcium hydroxide, calcium carbonate, sodium bicarbonate, magnesium carbonate, and other alkali or alkaline earth metal hydroxides and carbonates. Combinations of stabilizers can be used if desired. Preferably, calcium carbonate is used as a stabilizer.

One or more stabilizers can be used in an amount of at least 1 wt-%, or at least 2 wt-%, based on the total weight of the particle core. One or more stabilizers can be used in an amount of up to 10 wt-%, or up to 5 wt-%, based on the total weight of the particle core. In certain embodiments, the particle cores of the capsules of the present disclosure include 2 wt-% to 10 wt-% stabilizer(s), based on the total weight of an uncoated particle core.

Suitable release controlling agents for use in the coating on the particle core include, but are not limited to, ethylcellulose, polyvinyl acetate, polyacrylate and polymethacrylate (e.g., Ammonio Methacrylate Copolymer, Type A and Type B; Ethyl Acrylate and Methyl Methacrylate Copolymer), and copolymers thereof. Combinations of release controlling agents can be used if desired. Preferably, ethylcellulose (such as that available from The Dow Chemical Company under the trade designation ETHOCEL Standard 10 Premium) is used as a release controlling agent.

One or more release controlling agents can be used in an amount of at least 45 wt-%, or at least 50 wt-%, or at least 55 wt-%, or at least 60 wt-%, based on the total weight of the coating. One or more release controlling agents can be used in an amount of up to 80 wt-%, or up to 70 wt-%, or up to 65 wt-%, or up to 62 wt-%, based on the total weight of the coating. In certain embodiments, the particle coatings include 55 wt-% to 65 wt-% release control agent(s), based on the total weight of the coating. In certain embodiments, the particle coatings include 60 wt-% to 62 wt-% release control agent(s), based on the total weight of the coating.

Herein, “based on the total weight of the coating” means the total weight of the non-volatile components of the coating (e.g., release controlling agent, pore former, and plasticizer).

Pore formers that are suitable for use in the coating formulation include, but are not limited to, hypromellose, hydroxypropyl cellulose, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, polyethylene glycol, guar gum, xanthan gum, sodium alginate, povidone (i.e., polyvinylpyrrolidone), crospovidone, sodium starch glycolate, croscarmellose sodium, starch (e.g., pregelatinized starch), carbohydrates (e.g., mannitol, glucose, sucrose, fructose, mannose, galactose, sorbitol, and dextran), sodium chloride, potassium chloride, and calcium chloride. Preferred pore formers for use in the coating on the particle core include, but are not limited to, hydroxypropyl methylcellulose (“HPMC” such as hypromellose 2910 USP available under the trade name METHOCEL E5 Premium, METHOCEL E15 Premium), carboxymethylcellulose, methylcellulose, croscarmellose sodium, povidone, sodium starch glycolate, starch (e.g., pregelatinized starch), alginic acid, guar gum, and polyethylene glycol. Combinations of pore formers can be used if desired. Preferably, hydroxypropyl methylcellulose (hypromellose 2910) is used as a pore former (such as that available from The Dow Chemical Company under the trade designation METHOCEL E5 Premium).

One or more pore formers can be used in an amount of at least 5 wt-%, or at least 10 wt-%, or at least 15 wt-%, or at least 20 wt-%, or at least 22 wt-%, based on the total weight of the coating. One or more pore formers can be used in an amount of up to 30 wt-%, or up to 26 wt-%, or up to 25 wt-%, or up to 24 wt-%, based on the total weight of the coating. In certain embodiments, the particle coatings include 20 wt-% to 25 wt-% pore former(s), based on the total weight of the coating. In certain embodiments, the particle coatings include 22 wt-% to 24 wt-% pore former(s), based on the total weight of the coating.

Suitable plasticizers for use in the coating on the particle core include, but are not limited to, diethyl phthalate, triethyl citrate, dibutyl sebacate, polyethylene glycol, triacetin, tributyl citrate, glycerol, and propylene glycol. Combinations of plasticizers can be used if desired. Preferably, diethyl phthalate is used as a plasticizer.

One or more plasticizers can be used in an amount of at least 5 wt-%, or at least 10 wt-%, or at least 15 wt-%, based on the total weight of the coating. One or more plasticizers can be used in an amount of up to 30 wt-%, or up to 20 wt-%, or up to 18 wt-%, based on the total weight of the coating. In certain embodiments, the particle coatings include 10 wt-% to 20 wt-% plasticizer(s), based on the total weight of the coating. In certain embodiments, the particle coatings include 15 wt-% to 18 wt-% plasticizer(s), based on the total weight of the coating.

The coating solution typically includes the “solids” or non-volatile components (e.g., ethylcellulose, hypromellose 2910 and diethyl phthalate) along with solvents, such as a mixture of alcohol and water, such that the concentration of the non-volatile components in the coating solution is 5 wt-% to 10 wt-%. In an exemplary solution, the solvents are dehydrated alcohol and purified water in a weight ratio of 3.7:1.

Particles can be coated with a coating composition as described herein using conventional techniques known to one of skill in the art. Briefly, such coating techniques include bottom-spray fluid-bed coating (e.g., Würster), top-spray fluid-bed coating, and tangential-spray fluid-bed coating. Typically, such methods result in a coating that is substantially uniform on each individual particle.

An amount of coated particles sufficient to deliver the desired dose may be encapsulated into a capsule of any desirable size, for example, a size 000, 00, Oel, 0, 1, 2, 3, 4, or 5.

Components of a suitable capsule shell include, but are not limited to, hydroxypropyl methylcellulose and gelatin. Preferably, a capsule shell is a hydroxypropyl methylcellulose (HPMC) shell (e.g., at least 90 wt-% HPMC, based on the weight of the shell). Typically, commercially available HPMC capsules include small amounts of water, colorants (e.g., TiO₂ and iron oxides), and optionally gelling agents and gelling promoters. They have relatively low moisture content, making them suitable for moisture-sensitive materials. Such capsules resist breakage even at low moisture levels. HPMC capsules typically exhibit low solubility in ethanol, particularly in acidic media such as found in the stomach. Encapsulation of the particles of the present disclosure in such an HPMC capsule shell preferably reduces dose dumping (and immediate release) of topiramate from the coated particles (see “Alcohol Dose Dumping” experiment in the Examples Section).

The chemical stability of capsules of the present disclosure typically depends on humidity and/or water activity. Thus, it can be desirable to reduce exposure to excessive moisture during storage. This can be done, for example, by storing the capsules of the present disclosure in a container, particularly a sealed container that includes a desiccant. If a desiccant is used, the ratio of weight of desiccant to weight of filled capsules can be at least 0.01, or at least 0.1, or at least 0.25, and can be up to 0.9.

Suitable containers include, for example, high density polyethylene (HDPE). Such containers can be bottles with screw caps, or the like. Preferably, such bottles are sealed, particularly induction sealed, in addition to a boundary layer provided by the screw cap.

Suitable desiccants include, for example, silica gel, bentonite clay, and molecular sieve. Combinations of desiccants can be used if desired.

Capsules of the present disclosure are preferably chemically stable. That is, capsules of the present disclosure retain a potency of at least 90% after a given time period of storage in a sealed container at 25° C. and 60% relative humidity (RH). They also demonstrate little or no decomposition after a given time period such that no more than 2000 parts per million (ppm) each of sulfate or sulfamate decomposition products are produced (see Examples Section). In this context, the given time period is preferably at least 12 months (typically, without any packaging), or at least 24 months (potentially, without any packaging, although packaging, e.g., sealed container and desiccant as described herein would be preferred to achieve chemical stability for this length of time), or at least 36 months (typically, with packaging, e.g., sealed container and desiccant as described herein).

The present disclosure also provides methods of dosing a subject in need thereof. Such dosing could be for the treatment of convulsions (e.g., convulsions associated with epilepsy). Such dosing could be for prophylactic treatment, for example, of a migraine. Such dosing methods include administering a topiramate capsule. In certain embodiments, once-per-day dosing of the capsule of the present disclosure occurs in the morning. In certain embodiments, once-per-day dosing of the capsule of the present disclosure occurs in the evening.

In certain embodiments, the extended-release topiramate capsules of the present disclosure, when dosed to a healthy human subject once daily (e.g., in the morning or evening), achieves at steady-state, an AUC_(0-24h), C_(max), and C_(min) in the subject's plasma that are within the 80% to 125% bioequivalence criteria compared to immediate-release topiramate dosed twice per day (where the once-daily dose contains 2x the topiramate active agent as the individual immediate-release doses).

In this context, two treatments are bioequivalent at steady state (i.e., they are not different from one another) if the 90% confidence interval (CI) of the least squares geometric mean of one formulation-to-another formulation (e.g., capsules of the present disclosure to once-daily dose topiramate) ratio for each pharmacokinetic (PK) parameter (e.g., AUC_(0-24h), C_(max), and C_(min)) is completely contained within the 80-125% interval.

In certain embodiments, the extended-release topiramate capsules of the present disclosure, when dosed to a healthy human subject once daily in the morning, achieves at steady-state, a reduction of fluctuation index of at least 15% compared to immediate-release topiramate dosed twice per day. In certain embodiments, the reduction of fluctuation index is at least 20% compared to immediate-release topiramate dosed twice per day. In certain embodiments, the reduction of fluctuation index is at least 25% compared to immediate-release topiramate dosed twice per day.

In certain embodiments, the extended-release topiramate capsules of the present disclosure, when dosed to a healthy human subject once daily in the morning, achieves at steady-state, a C_(min) in the subject's plasma that is higher than the C_(min) compared to immediate-release topiramate dosed twice per day.

In certain embodiments, the extended-release topiramate capsules of the present disclosure, when given as a single-dose to a healthy human subject, achieves an AUC_(0-inf) of 170 to 210 h·μg/mL within a 95% confidence interval, and a C_(max) of 2 to 4 μg/mL within a 95% confidence interval.

Capsules of the present disclosure demonstrate a reduced level of side effects compared to other topiramate products. For example, in certain embodiments, the extended-release topiramate capsules of the present disclosure, when dosed once daily to a population of human patients suffering from epilepsy, achieves a reduction in incidence of at least one side effect compared to immediate-release topiramate dosed at the same total daily dose divided twice per day. This comparison is based on the extended-release topiramate capsules of the present disclosure compared to placebo, and the immediate-release topiramate (TOPAMAX) compared to placebo. The term “incidence” refers to the percentage of patients who experience a new side effect during the study. The at least one side effect includes somnolence, dizziness, ataxia, disturbance in attention, memory impairment, cognitive disorder, and psychomotor slowing.

LIST OF EXEMPLARY EMBODIMENTS

-   1. An extended-release topiramate capsule comprising:     -   a capsule shell comprising (or consisting essentially of, or         consisting of) a single population of coated particles;         -   wherein each coated particle comprises a core and a coating             thereon;         -   wherein each particle core comprises a homogeneous mixture             comprising topiramate throughout its core; and         -   wherein the coating comprises one or more release             controlling agent(s). -   2. The capsule of embodiment 1 wherein:     -   each particle core comprises a homogeneous mixture comprising:         -   topiramate;         -   one or more filler(s); and         -   one or more binder(s); and     -   the coating comprises:         -   one or more release controlling agent(s);         -   one or more pore former(s); and         -   one or more plasticizer(s). -   3. An extended-release topiramate capsule comprising (or consisting     essentially of, or consisting of):     -   a capsule shell comprising (or consisting essentially of, or         consisting of) a single population of coated particles;         -   wherein each coated particle comprises (or consists             essentially of, or consists of) a core and a coating             thereon;         -   wherein each particle core comprises (or consists             essentially of, or consists of) a homogeneous mixture             throughout its core, the mixture comprising (or consisting             essentially of, or consisting of):             -   40 wt-% to 50 wt-% of topiramate, based on the total                 weight of an uncoated particle core;             -   45 wt-% to 55 wt-% of one or more filler(s), based on                 the total weight of an uncoated particle core; and             -   3 wt-% to 7 wt-% of one or more binder(s), based on the                 total weight of an uncoated particle core;

wherein the coating comprises (or consists essentially of, or consists of):

-   -   -   55 wt-% to 65 wt-% of one or more release control agent(s),             based on the total weight of the coating;         -   20 wt-% to 25 wt-% of one or more pore former(s), based on             the total weight of the coating; and         -   10 wt-% to 20 wt-% of one or more plasticizer(s), based on             the total weight of the coating;

    -   wherein the particles are coated in an amount sufficient to         provide a weight gain of 8% to 14%.

-   4. The extended-release topiramate capsule of any of embodiments 1     through 3 wherein the particles are coated in an amount sufficient     to provide a weight gain of 10% to 12%.

-   5. The extended-release topiramate capsule of any of embodiments 1     through 4 wherein the one or more filler(s) is selected from the     group of microcrystalline cellulose, dibasic calcium phosphate,     lactose, tribasic calcium phosphate, mannitol, and combinations     thereof.

-   6. The extended-release topiramate capsule of embodiment 5 wherein     the filler is microcrystalline cellulose.

-   7. The extended-release topiramate capsule of any of embodiments 1     through 6 wherein the one or more binder(s) is selected from the     group of hydroxypropyl methylcellulose, methylcellulose,     carboxymethylcellulose, sodium carboxymethylcellulose, hydroxypropyl     cellulose, hydroxyethylcellulose, polyvinyl pyrrolidine, starch,     natural gum, and combinations thereof.

-   8. The extended-release topiramate capsule of embodiment 7 wherein     the binder is hydroxypropyl methylcellulose.

-   9. The extended-release topiramate capsule of any of embodiments 1     through 8 wherein the one or more release controlling agent(s) is     selected from the group of ethylcellulose, polyvinyl acetate,     polyacrylate and polymethacrylate, copolymers thereof, and     combinations thereof.

-   10. The extended-release topiramate capsule of embodiment 9 wherein     the release controlling agent is ethylcellulose.

-   11. The extended-release topiramate capsule of any of embodiments 1     through 10 wherein the one or more pore former(s) is selected from     the group of hypromellose, hydroxypropyl cellulose, methylcellulose,     hydroxyethylcellulose, carboxymethylcellulose, sodium     carboxymethylcellulose, polyethylene glycol, guar gum, xanthan gum,     sodium alginate, polyvinylpyrrolidone, crospovidone, sodium starch     glycolate, croscarmellose sodium, starch, mannitol, glucose,     sucrose, fructose, mannose, galactose, sorbitol, dextran, sodium     chloride, potassium chloride, calcium chloride, and combinations     thereof

-   12. The extended-release topiramate capsule of embodiment 11 wherein     the pore former is hydroxypropyl methylcellulose.

-   13. The extended-release topiramate capsule of any of embodiments 1     through 12 wherein the one or more plasticizer(s) is selected from     the group of diethyl phthalate, triethyl citrate, dibutyl sebacate,     polyethylene glycol, triacetin, tributyl citrate, glycerol,     propylene glycol, and combinations thereof

-   14. The extended-release topiramate capsule of embodiment 13 wherein     the plasticizer is diethyl phthalate.

-   15. The extended-release topiramate capsule of any of embodiments 1     through 14 wherein each particle core further comprises one or more     stabilizer(s).

-   16. The extended-release topiramate capsule of embodiment 15 wherein     the one or more stabilizer(s) is selected from the group of calcium     hydroxide, calcium carbonate, sodium bicarbonate, magnesium     carbonate, and combinations thereof

-   17. The extended-release topiramate capsule of embodiment 15 or 16     wherein the one or more stabilizer(s) is present in an amount of 2     wt-% to 10 wt-%, based on the total weight of an uncoated particle     core.

-   18. An extended-release topiramate capsule comprising (or consisting     essentially of, or consisting of):     -   a capsule shell comprising (or consisting essentially of, or         consisting of) a single population of coated particles;         -   wherein each coated particle comprises (or consists             essentially of, or consists of) a core and a coating             thereon;         -   wherein each particle core comprises (or consists             essentially of, or consists of) a homogeneous mixture             throughout its core, the mixture comprising (or consisting             essentially of, or consisting of):             -   40 wt-% to 50 wt-% of topiramate, based on the total                 weight of an uncoated particle core;             -   45 wt-% to 55 wt-% of one or more filler(s), based on                 the total weight of an uncoated particle core; wherein                 the one or more filler(s) is selected from the group of                 microcrystalline cellulose, dibasic calcium phosphate,                 lactose, tribasic calcium phosphate, mannitol, and                 combinations thereof; and             -   3 wt-% to 7 wt-% of one or more binder(s), based on the                 total weight of an uncoated particle core; wherein the                 one or more binder(s) is selected from the group of                 hydroxypropyl methylcellulose, methylcellulose,                 carboxymethylcellulose, sodium carboxymethylcellulose,                 hydroxypropyl cellulose, hydroxyethylcellulose,                 polyvinyl pyrrolidine, starch, natural gum, and                 combinations thereof;     -   wherein the coating comprises (or consists essentially of, or         consists of):         -   -   55 wt-% to 65 wt-% of one or more release control                 agent(s), based on the total weight of the coating;                 wherein the one or more release controlling agent(s) is                 selected from the group of ethylcellulose, polyvinyl                 acetate, polyacrylate and polymethacrylate, copolymers                 thereof, and combinations thereof;             -   20 wt-% to 25 wt-% of one or more pore former(s), based                 on the total weight of the coating; wherein the one or                 more pore former(s) is selected from the group of                 hypromellose, hydroxypropyl cellulose, methylcellulose,                 hydroxyethylcellulose, carboxymethylcellulose, sodium                 carboxymethylcellulose, polyethylene glycol, guar gum,                 xanthan gum, sodium alginate, polyvinylpyrrolidone,                 crospovidone, sodium starch glycolate, croscarmellose                 sodium, starch, mannitol, glucose, sucrose, fructose,                 mannose, galactose, sorbitol, dextran, sodium chloride,                 potassium chloride, calcium chloride, and combinations                 thereof; and             -   10 wt-% to 20 wt-% of one or more plasticizer(s), based                 on the total weight of the coating; wherein the one or                 more plasticizer(s) is selected from the group of                 diethyl phthalate, triethyl citrate, dibutyl sebacate,                 polyethylene glycol, triacetin, tributyl citrate,                 glycerol, propylene glycol, and combinations thereof;     -   wherein the particles are coated in an amount sufficient to         provide a weight gain of 8% to 14%.

-   19. An extended-release topiramate capsule comprising (or consisting     essentially of, or consisting of):     -   a capsule shell comprising (or consisting essentially of, or         consisting of) a single population of coated particles;         -   wherein each coated particle comprises (or consists             essentially of, or consists of) a core and a coating             thereon;         -   wherein each particle core comprises (or consists             essentially of, or consists of) a homogeneous mixture             throughout its core, the mixture comprising (or consisting             essentially of, or consisting of):             -   40-50 wt-% of topiramate, based on the total weight of                 an uncoated particle core;             -   45-55 wt-% of microcrystalline cellulose, based on the                 total weight of an uncoated particle core; and             -   3-7 wt-% of hydroxypropyl methylcellulose, based on the                 total weight of an uncoated particle core;     -   wherein the coating comprises (or consists essentially of, or         consists of):         -   -   55-65 wt-% of ethylcellulose, based on the total weight                 of the coating;             -   20-25 wt-% of hydroxypropyl methylcellulose, based on                 the total weight of the coating; and             -   10-20 wt-% of diethyl phthalate, based on the total                 weight of the coating;     -   wherein the particles are coated in an amount sufficient to         provide a weight gain of 8% to 14%.

-   20. An extended-release topiramate capsule comprising (or consisting     essentially of, or consisting of):     -   a capsule shell comprising (or consisting essentially of, or         consisting of) a single population of coated particles;         -   wherein each coated particle comprises (or consists             essentially of, or consists of) a core and a coating             thereon;         -   wherein each particle core comprises (or consists             essentially of, or consists of) a homogeneous mixture             throughout its core, the mixture comprising (or consisting             essentially of, or consisting of):             -   44-46 wt-% of topiramate, based on the total weight of                 an uncoated particle core;             -   48-52 wt-% of microcrystalline cellulose, based on the                 total weight of an uncoated particle core; and             -   4-6 wt-% of hydroxypropyl methylcellulose, based on the                 total weight of an uncoated particle core;     -   wherein the coating comprises (or consists essentially of, or         consists of):         -   -   60-62 wt-% of ethylcellulose, based on the total weight                 of the coating;             -   22-24 wt-% of hydroxypropyl methylcellulose, based on                 the total weight of the coating; and             -   15-18 wt-% of diethyl phthalate, based on the total                 weight of the coating;     -   wherein the particles are coated in an amount sufficient to         provide a weight gain of 10-12%.

-   21. The extended-release topiramate capsule of any of embodiments 1     through 20 which, when dosed to a healthy human subject once daily     (e.g., in the morning or evening), achieves at steady-state, an     AUC_(0-24h), C_(max), and C_(min), in the subject's plasma that are     within the 80% to 125% bioequivalence criteria compared to     immediate-release topiramate dosed twice per day.

-   22. The extended-release topiramate capsule of any of embodiments 1     through 21 which, when dosed to a healthy human subject once daily     in the morning, achieves at steady-state, a reduction of fluctuation     index of at least 15% compared to immediate-release topiramate dosed     twice per day.

-   23. The extended-release topiramate capsule of embodiment 22 which,     when dosed to a healthy human subject once daily in the morning,     achieves at steady-state, a reduction of fluctuation index of at     least 20% compared to immediate-release topiramate dosed twice per     day.

-   24. The extended-release topiramate capsule of embodiment 23 which,     when dosed to a healthy human subject once daily in the morning,     achieves at steady-state, a reduction of fluctuation index of at     least 25% compared to immediate-release topiramate dosed twice per     day.

-   25. The extended-release topiramate capsule of any of embodiments 1     through 24 which, when dosed to a healthy human subject once daily     in the morning, achieves at steady-state, a C_(min) in the subject's     plasma that is higher than the C_(min) compared to immediate-release     topiramate dosed twice per day.

-   26. The extended-release topiramate capsule of any of embodiments 1     through 25 which, when given as a single-dose to a healthy human     subject, achieves an AUC_(0-inf) of 170 to 210 h·μg/mL within a 95%     confidence interval, and a C_(max) of 2 to 4 μg/mL within a 95%     confidence interval.

-   27. The extended-release topiramate capsule of any of embodiments 1     through 26 which, when dosed once daily to a population of human     patients suffering from epilepsy, achieves a reduction in incidence     of at least one side effect compared to immediate-release topiramate     dosed at the same total daily dose divided twice per day.

-   28. The extended-release topiramate capsule of any of embodiments 1     through 27 which is chemically stable for at least 12 months.

-   29. The extended-release topiramate capsule of embodiment 28 which     is chemically stable for at least 24 months.

-   30. The extended-release topiramate capsule of embodiment 29 which     is chemically stable for at least 24 months when stored in a sealed     container with desiccant.

-   31. The extended-release topiramate capsule of embodiment 30 which     is chemically stable for at least 36 months when stored in a sealed     container with desiccant.

-   32. The extended-release topiramate capsule of any of embodiments 1     through 31 which is free of an immediate release component.

-   33. The extended-release topiramate capsule of any of embodiments 1     through 32 wherein the coated particles have a sphericity of at     least 0.7.

-   34. The extended-release topiramate capsule of any of embodiments 1     through 33 wherein the coated particles have a particle size of at     least 500 μm.

-   35. The extended-release topiramate capsule of any of embodiments 1     through 34 wherein the coated particles have a particle size of up     to 1300 μm.

-   36. The extended-release topiramate capsule of any of embodiments 1     through 35 wherein the capsule shell comprises hydroxypropyl     methylcellulose or gelatin.

-   37. The extended-release topiramate capsule of embodiment 36 wherein     the capsule shell is a hydroxypropyl methylcellulose capsule.

-   38. A container comprising an extended-release topiramate capsule of     any of embodiments 1 through 37 and desiccant.

-   39. The container of embodiment 38 wherein the ratio of weight of     desiccant to weight of filled capsules is at least 0.01.

-   40. The container of embodiment 38 or 39 wherein the ratio of weight     of desiccant to weight of filled capsules is up to 0.9.

-   41. The container of any of embodiments 38 through 40 wherein the     desiccant is selected from silica gel, bentonite clay, molecular     sieve, and combinations thereof.

-   42. A method of dosing a subject in need thereof, the method     comprising administering an extended-release topiramate capsule of     any of embodiments 1 through 37 once daily to the subject.

-   43. The method of embodiment 42 wherein the administering occurs     once daily in the morning.

-   44. The method of embodiment 42 wherein the administering occurs     once daily in the evening.

-   45. The method of any of embodiments 42 through 44 wherein the     dosing is for the treatment of convulsions.

-   46. The method of any of embodiments 42 through 44 wherein the     dosing is for the prophylactic treatment of a migraine.

EXAMPLES Process and Formulations

-   -   1. High Shear Granulation: The core bead components listed in         the table below are added to the high shear granulator and         blended. After the pre-mix step, Purified Water is added to the         high shear granulator and the mixture kneaded to create a wet         granulation.     -   2. Extrusion: The wet granulation is then fed at a specified         rate into a twin dome extruder equipped with dome dies having         0.8 mm pores to form an extrudate.     -   3. Spheronization: Portions of the extrudate from the extruder         are weighed out and processed, for a specified time sufficient         to form spherical particles (i.e., beads), in a spheronizer         equipped with a 2×2 mm friction plate.     -   4. Drying: The wet spherical particles are dried in a fluid bed         processor to a moisture content of not more than (NMT) 3.0% w/w,         as determined by an in-process loss-on-drying analysis.     -   5. Sizing: The dried particles are sized using a 14-mesh and a         30-mesh sieve (Market Grade mesh screen). Material passing         through the 14-mesh sieve, but retained on the 30-mesh sieve is         taken into the subsequent coating step.     -   6. Coating: The dried, sized, uncoated beads are coated in a         Würster fluidized bed processor to a desired coating weight gain         using the coating composition listed in the table below.     -   7. Sizing: Following coating, the beads are sized using a         14-mesh and a 30-mesh sieve (Market Grade mesh screen). Material         passing through the 14-mesh sieve, but retained on the 30-mesh         sieve is taken into the subsequent encapsulation step.     -   8. Encapsulation: Using a suitable encapsulator, appropriate         amounts of coated beads are filled into appropriate size         capsules to yield the different strengths of the product. The         encapsulated product is also run through a capsule polisher,         metal detector, and weight checker.

Formulation designation A B Coating Weight Gain** 12% w/w 10% w/w Core particle components (% w/w, based on weight of the core) Topiramate 45 45 Microcrystalline Cellulose 50 50 Hypromellose 2910 5 5 Coating components*** (% w/w, based on weight of the coating) Ethylcellulose 60.86 60.86 Hypromellose 2910 22.56 22.56 Diethyl Phthalate 16.58 16.58 Dehydrated Alcohol* NA NA Purified Water* NA NA *Removed during processing. **Weight gain is defined as the theoretical weight gain after coating of a population of uncoated particles, assuming 100% coating efficiency. ***The solids content (non-volatile components, i.e., ethylcellulose, hypromellose 2910 and diethyl phthalate) of the coating solution was 7.5% w/w for B and 6% w/w for A. The ratio of Dehydrated Alcohol to Purified Water is about 3.7:1on a weight basis.

PK Results

In clinical studies, the extended-release topiramate capsules of Formulation A, when given as a single-dose to a healthy human subject, achieved an AUC_(0-inf) of 173.9 to 200.1 h·μg/mL within a 95% confidence interval, and a C_(max) of 2.64 to 3.16 μg/mL within a 95% confidence interval.

In clinical studies, the extended-release topiramate capsules of Formulation B, when given as a single-dose to a healthy human subject, achieved an AUC_(0-inf) of 179.7 to 204.3 h·μg/mL within a 95% confidence interval, and a C_(max) of 2.94 to 3.43 μg/mL within a 95% confidence interval.

Adverse Event Evaluation

In clinical studies, the extended-release topiramate capsules of the present disclosure, when dosed to patients with epilepsy (more specifically, as adjunctive treatment in patients with refractory partial onset seizure with or without generalization) once daily, achieved a reduction in incidence of at least one side effect compared to immediate-release topiramate dosed at the same total daily dose divided twice per day.

This comparison is based on the extended-release topiramate capsules of the present disclosure compared to placebo, and the immediate-release topiramate (TOPAMAX) compared to placebo. Each being compared to placebo (as opposed to each other), this evaluation demonstrated that the extended-release topiramate capsules of the present disclosure achieve a reduction in at least one side effect (e.g., somnolence, dizziness, ataxia, disturbance in attention, memory impairment, cognitive disorder, and psychomotor slowing).

Alcohol Dose Dumping

Capsules of the present disclosure, which included an ethanol-soluble particle coating, were evaluated in vitro for dose dumping in ethanol using a USP apparatus 1 (baskets) operating at 100 revolutions per minute (rpm) with a pH 1.2 HCl buffer containing 5 to 40% v/v (volume by volume) ethanol. There was no evidence of immediate release or unacceptable acceleration of release of the topiramate.

Sulfate/Sulfamate Method

Sulfate and Sulfamate degradation products were measured utilizing an ion chromatography (IC) method with ion suppression conductivity detection. The chromatographic system used an Alltech Novosep A-2, 250×4.0 mm, 5-μm particle size column maintained at 43° C. The flow rate of the 3.6 mM sodium carbonate mobile phase was 1.0 mL/min. A 7 mg/mL solution of topiramate in water containing 10% acetonitrile was prepared from particles (removed from a capsule of the present disclosure) using sonication and mixing to extract the sulfate and sulfamate degradation products. Particles within the capsules of the present disclosure demonstrated little or no decomposition after a given time period, such that no more than 2000 parts per million (ppm) each of sulfate or sulfamate degradation products were produced.

The complete disclosures of the patents, patent documents, and publications cited herein are incorporated by reference in their entirety as if each were individually incorporated. Various modifications and alterations to this disclosure will become apparent to those skilled in the art without departing from the scope and spirit of this disclosure. It should be understood that this disclosure is not intended to be unduly limited by the illustrative embodiments and examples set forth herein and that such examples and embodiments are presented by way of example only with the scope of the disclosure intended to be limited only by the claims set forth herein as follows. 

1-30. (canceled)
 31. An extended-release topiramate capsule comprising: a capsule shell comprising a single population of coated particles; wherein each coated particle comprises a core and a coating thereon; wherein each particle core comprises a homogeneous mixture comprising topiramate throughout its core; and wherein the coating comprises one or more release controlling agent(s).
 32. The capsule of claim 31 wherein: each particle core comprises a homogeneous mixture comprising: topiramate; one or more filler(s); and one or more binder(s); and the coating comprises: one or more release controlling agent(s); one or more pore former(s); and one or more plasticizer(s).
 33. The extended-release topiramate capsule of claim 31 wherein the particles are coated in an amount sufficient to provide a weight gain of 10% to 12%.
 34. The extended-release topiramate capsule of claim 31 wherein the one or more filler(s) is selected from the group of microcrystalline cellulose, dibasic calcium phosphate, lactose, tribasic calcium phosphate, mannitol, and combinations thereof.
 35. The extended-release topiramate capsule of claim 31 wherein the one or more binder(s) is selected from the group of hydroxypropyl methylcellulose, methylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, hydroxypropyl cellulose, hydroxyethylcellulose, polyvinyl pyrrolidine, starch, natural gum, and combinations thereof.
 36. The extended-release topiramate capsule of claim 31 wherein the one or more release controlling agent(s) is selected from the group of ethylcellulose, polyvinyl acetate, polyacrylate and polymethacrylate, copolymers thereof, and combinations thereof.
 37. The extended-release topiramate capsule of claim 31 wherein the one or more pore former(s) is selected from the group of hypromellose, hydroxypropyl cellulose, methylcellulose, hydroxyethylcellulose, carboxymethylcellulose, sodium carboxymethylcellulose, polyethylene glycol, guar gum, xanthan gum, sodium alginate, polyvinylpyrrolidone, crospovidone, sodium starch glycolate, croscarmellose sodium, starch, mannitol, glucose, sucrose, fructose, mannose, galactose, sorbitol, dextran, sodium chloride, potassium chloride, calcium chloride, and combinations thereof.
 38. The extended-release topiramate capsule of claim 31 wherein the one or more plasticizer(s) is selected from the group of diethyl phthalate, triethyl citrate, dibutyl sebacate, polyethylene glycol, triacetin, tributyl citrate, glycerol, propylene glycol, and combinations thereof.
 39. The extended-release topiramate capsule of claim 31 wherein each particle core further comprises one or more stabilizer(s).
 40. The extended-release topiramate capsule of claim 39 wherein the one or more stabilizer(s) is selected from the group of calcium hydroxide, calcium carbonate, sodium bicarbonate, magnesium carbonate, and combinations thereof.
 41. The extended-release topiramate capsule of claim 31 which, when dosed to a healthy human subject once daily (e.g., in the morning or evening), achieves at steady-state, an AUC_(0-24h), C_(max) and C_(min) in the subject's plasma that are within the 80% to 125% bioequivalence criteria compared to immediate-release topiramate dosed twice per day.
 42. The extended-release topiramate capsule of claim 31 which, when dosed to a healthy human subject once daily in the morning, achieves at steady-state, a reduction of fluctuation index of at least 15% compared to immediate-release topiramate dosed twice per day.
 43. The extended-release topiramate capsule of claim 31 which, when dosed to a healthy human subject once daily in the morning, achieves at steady-state, a C_(min) in the subject's plasma that is higher than the C_(min) compared to immediate-release topiramate dosed twice per day.
 44. The extended-release topiramate capsule of claim 31 which, when given as a single-dose to a healthy human subject, achieves an AUC_(0-inf) of 170 to 210 h·μg/mL within a 95% confidence interval, and a C_(min) of 2 to 4 μg/mL within a 95% confidence interval.
 45. The extended-release topiramate capsule of claim 31 which, when dosed once daily to a population of human patients suffering from epilepsy, achieves a reduction in incidence of at least one side effect compared to immediate-release topiramate dosed at the same total daily dose divided twice per day.
 46. The extended-release topiramate capsule of claim 31 which is chemically stable for at least 12 months.
 47. The extended-release topiramate capsule of claim 46 which is chemically stable for at least 24 months when stored in a sealed container with desiccant.
 48. The extended-release topiramate capsule of claim 31 which is free of an immediate release component.
 49. The extended-release topiramate capsule of claim 31 wherein the coated particles have a sphericity of at least 0.7.
 50. The extended-release topiramate capsule of claim 31 wherein the coated particles have a particle size of at least 500 μm.
 51. The extended-release topiramate capsule of claim 31 wherein the coated particles have a particle size of up to 1300 μm.
 52. The extended-release topiramate capsule of claim 31 wherein the capsule shell comprises hydroxypropyl methylcellulose or gelatin.
 53. A container comprising an extended-release topiramate capsule of claim 31 and desiccant.
 54. The container of claim 53 wherein the ratio of weight of desiccant to weight of filled capsules is at least 0.01.
 55. The container of claim 53 wherein the ratio of weight of desiccant to weight of filled capsules is up to 0.9.
 56. The container of claim 53 wherein the desiccant is selected from silica gel, bentonite clay, molecular sieve, and combinations thereof.
 57. A method of dosing a subject in need thereof, the method comprising administering an extended-release topiramate capsule of claim 31 once daily to the subject.
 58. The method of claim 57 wherein the administering occurs once daily in the morning.
 59. The method of claim 57 wherein the administering occurs once daily in the evening.
 60. The method of claim 57 wherein the dosing is for the treatment of convulsions.
 61. The method of claim 57 wherein the dosing is for the prophylactic treatment of a migraine. 